What is the test for provocation in the context of a voluntary manslaughter instruction?

Moreover, as we discuss below, we conclude that any error in the instructions or in argument was harmless under any standard of review because no evidence supported an instruction on voluntary manslaughter. "If the evidence in a case does not support instructions on voluntary manslaughter, the definition of provocation and heat of passion as relevant to voluntary manslaughter are immaterial. [Citation.]" (People v. Souza (2012) 54 Cal.4th 90, 118.) "[T]he factor which distinguishes the 'heat of passion' form of voluntary manslaughter from murder is provocation." (People v. Lee (1999) 20 Cal.4th 47, 59.) "The provocative conduct by the victim may be physical or verbal, but the conduct must be sufficiently provocative that it would cause an ordinary person of average disposition to act rashly or without due deliberation and reflection. [Citations.]" (Ibid.) "The test for adequate provocation is an objective one, however." (Id. at p. 60.)